An attempt by Deutsche Lufthansa to avert a planned cabin crew strike at the airline's Germanwings unit failed on Saturday as their trade union rejected management concessions as insufficient.

An offer by Lufthansa's short-haul budget division to enter mediation and make concessions on part-time working was jilted by cabin crew union UFO, which said it would proceed with the strike from Monday to Wednesday next week as announced on Friday.

The strike is an escalation of a months-long dispute with Lufthansa and its subsidiaries over pay and pensions.

Lufthansa cabin crew struck for two days in November, resulting in the cancellation of one in five flights, affecting around 180,000 passengers and costing the airline between EUR 10 and 20 million (US$11-US$22 million).